There are two ways to connect a GPS device to a car: connecting it to maintain a charge from the cigarette lighter plug and connecting it to use the FM stereo as an output for the audio from the GPS device.
Follow the instructions given by the specific brand of GPS device for physically attaching the device to the dashboard of your car.
Connect the power cord to the GPS device at its power input and plug the other end into the cigarette lighter plug.
Attach a patch cord to the audio output from the GPS device and attach the other end to the auxiliary input on your car's stereo. Find an open frequency and the audio should come in. This may prove difficult in an urban area.
